Method of sizing paper with chloroethyl sulfide or sulfone and paper thereof



United States Patent 3,345,251 METHOD OF SIZING PAPER WITH CHLOROETHYL SULFIDE OR SULFONE AND PAPER THEREOF Van R. Gaertner, Ballwin, Mo., assignor to Monsanto Company, St. Louis, Mo., a corporation of Delaware No Drawing. Filed Mar. 24, 1965, Ser. No. 442,502 12 Claims. (Cl. 162158) This invention relates to sized fibrous products such as cellulosic pulp, paper, cardboard, textile threads, fabrics and the like. This invention provides new sized products and process for preparing them.

It has been found, according to this'invention that fibrous materials, particularly fibers of cellulose and the like, may be advantageously sized by applying to the fibrous material a compound of the formula wherein R is any organic hydrocarbon hydrophobic group, and n is selected from an integer consisting of 0 and 2, and then drying the thus treated fibrous material. These Z-chloroethyl sulfides, and sulfones may applied by any convenient method known to those skilled in the sizing art but they are most conveniently applied in water-immiscible organic solvent solutions emulsified aqueous or dispersions suflicient to impart from about 0.1 to aout 5% or more by weight based on the weight of the dry fiber of the sulfur compound used. Not all sulfide, or sulfones are useful for this purpose but these compounds have been found to be efficient sizing agents at these low concentrations. For example, the hydroxyethyl and vinyl sulfides, sulfones are surprisingly much less effective as sizing agents than the above described 2-chloroethyl sulfides, and sulfones. Higher concentrations of these sulfur com pounds could also be applied to fibrous material if desired but for most practical purposes, higher concentrations are not generally needed. Lower concentrations of the sizing agent than those stated above could also be used to impart at least a degree of water repellant improvement but the range indicated is preferred.

The 2-chloroethyl hydrophobic sulfides, and sulfones which I have found to be useful for sizing fibrous materials, particularly cellulosic fibrous materials include those in which the hydrophobic group is a higher alkyl having at least about carbon atoms, e.g., decyl, undecyl, dodecyl, tridecyl, tetradecyl, pentadecyl, hexadecyl, heptadecyl, octadecyl, tetracosyl, and pentacosyl and higher alkyl up to about 40 carbon atoms if desired, although those having up to about 25 carbon atoms are preferred, the corresponding alkenyl groups having from 10 to about 40 carbon atoms, a few examples of which are decenyl, tri-decenyl, heptadecenyl, octadecenyl, eicosenyl, tricosenyl, etc., the alkylphenyl and alkyl substituted cycloalkyl having at least about 8 carbon atoms in the alkyl groups attached to the phenyl or cycloalkyl group, e.g., octylphenyl, dinonylphenyl, dodecylphenyl, tridecylphenyl, pentadecylphenyl, octadecylphenyl, heneicosylphenyl, nonylcyclopropyl, dodecylcyclobutyl, tridecylcyclopentyl, tetradecylcyclohexyl, pentadecylcycloheptyl, octadecylcyclohexyl, etc., and any of such alkyl, alkenyl, alkylphenyl and alkylcycloalkyl, 2-chlor0ethyl sulfide, or sulfone compounds containing non-interfering inert substituents. Inert substituents which may be present include groups such as carboalkoxy, alkyloxy, aryloxy, arylalkyloxy, keto(carbonyl, tertiary amide, halogen attached to aromatic carbons, or alphat-ic heterocyclic groups, i.e., aliphatic heterocyclic groups, i.e., heterocyclic radicals containing no benzene-type unsaturation. The heterocyclic radical may be saturated or unsaturated. Types of radicals which should not be present to any substantial extent in the hydrophobic group are exemplified by hydroxyl 3,345,251 Patented Oct. 3, 1967 groups, primary and secondary amino groups, labile halogens, amide groups having amido hydrogen, and carboxyl or other acidic groups. Those skilled in the art will be aware of the types of hydrophobic groups which may be used in these Z-chloroethyl sulfide, and sulfone compounds if undesired side reactions are to be avoided.

These sulfide, and sulfone compounds can be used as single pure compounds for the purpose of this invention. However, in commercial practice, 2-chloroethyl sulfide, and sulfone compounds containing, e.g., mixed hydrophobic alkyl, mixed alkenyl and alkyl, alkylphenyl, or alkyl, and alkyl-substituted cycloalkyl groups may conveniently be used. Mixtures of sulfides, and sulfones are also useful.

For some applications of these materials to some cellulosic fibrous, increased sizing eifectiveness is noted when these 2-chloroethyl sulfide, and sulfones are applied to the fibrous substrate admixed with or simultaneously with a basic material such as an alkali metal hydroxide in an amount sufiicient to efiect the sizing on the basic side of the pH range, that is, above pH 7. When this procedure is contemplated the base used will usually be sodium hydroxide because it is most readily available and the most economical one to use. However, it is understood that other basic materials such as potassium hydroxide, lime, hydrated lime, calcium hydroxide, and other alkali metal and alkaline earth metal bases and basic salts could be used if desired.

The sufide, and sulfone materials may be applied to fibrous substrates to impart sizing thereto in any conventional manner. The fibrous material in the form of cellulosic pulp, finished paper sheets or paper board, or paper product, textile fiber, thread, yarn, or fabric may be simply dipped into a water-immiscible organic solvent solution of the Z-chloroethyl sulfide, or sulfone, and then dried in any convenient manner. The term drying and its various adjective, verb, and participle forms, are

used herein to include curing of the treated fibrous substrate to give a finished sized fibrous product. The amount of the 2-chloroethyl sulfide, or sulfone retained by the fibrous substrate can be controlled by the concentration of the treating solution and the degree of squeezing or pressing of the dipped fibrous material before drying.

This invention also contemplates the use of these sizing agents in conjunction with agents designed to increase retention of the sizing agents by the fibrous substrate such as cellulosic fibers. Useful auxiliary agents of this type inslude cationic starch, a good example of which is a modified cornstarch having a nitrogen content of about 0.25 percent, sold under the tradename Cato 8 by National Starch Products Company. When from about 0.1% to about 0.5% by weight, based on the weight of the fibrous substrate, e.g., cellulose pulp, of a cationic starch, such as Cato 8 is added to the stock slurry before, after, or simultaneously with the sizing agent, a decided improvement in retention of the sizing agent is obtained.

'The sizing agents of this invention may also be combined with a cationic emulsifying agent in a water-immiscible organic solvent solution, say, at concentrations of from about 5 percent to percent by weight of the sizing agent, together with a small but effective amount, usually in concentrations of from 1 to 5% by weight of a cationic surface active agent, examples of which include the quaternary ammonium salts of long chain amines, such as cetyltriethylammonium chloride, of acyl derivatives of diethylethylenediamine such as the methoxysulfonate of oleoyldiethylmethylethylenediamine, the alkylbenzyldimethylammoniurn chlorides, etc., in an organic solvent solution, which solution emulsifies well in and is diluted by the aqueous slurries or dispersions of fibrous J material such as cellulosic paper pulp, to which it is added. Solutions of high concentrations of the sizing agent, with or without the retention aid, may be metered by conventional methods to aqueous slurries of fibrous substrates to impart the desired low concentration of sizing agent to the size fibrous materials.

The effectiveness of these 2-chloroethyl sulfide, and sulfones as sizing agents is illustrated by the following example.

EXAMPLE 1 Pieces of unsized cellulosic paper were dipped into solutions of either n-octadecyl 2-chloroethy1 sulfide or n-octadecyl 2-chloroethyl sulfone in chloroform. The concentration of the respective sulfide or sulfone ranged from 0.35% by weight to 0.42% by weight. In some of the solutions, sodium hydroxide was added to the solution of the respective sulfide or sulfone in an amount equivalent to 1% by weight of the solution. After the paper samples were dipped into the respective solutions, the treated papers were dried and cured by one of the following methods:

(A) The treated paper was placed in a forced air drying oven for 90 minutes at 105 C.

(B) The treated paper was dried on the standard Noble-Wood handsheet paper drier.

(C) The treated paper was placed in the forced air drying oven for 60 minutes at 105 C.

Some of the treated paper samples were soaked in acetone solution overnight and then re-dried before testing to determine the permanency of the sizing agent.

The dried treated paper sheets were tested for sizing by forming a small flat bottomed boat of the treated paper and floating the treated paper on a standard ink bath in a constant temperature, humidity, and pressure room. The time, in seconds, for the first indication of ink appearance on the upper observed surface, is noted. The results of this test were as follows:

Sizing-Ink Flotation Drying Method (seconds) Sizing Chemical and Concentration Method As Is 1 Washed 0.42%, by Wt 2, 500

0.42%, plus 1% NAOH 1, 800 950 OQWOWP 0.35% Q 0 0.35%, plus 0.5% NAOH 1, 700 sulfone:

o 0.35%, plus 0.5% NAOH Control 3 These data illustrate the substantial sizing effectiveness of these compounds on cellulosic fibrous materials.

I claim:

1. A fibrous product comprising cellulose fibers having distributed on their surface about 0.1 percent to about 5 percent by weight on the dry fibers of a compound of the formula where R is selected from the group consisting of alkyl groups and alkylphenyl groups having at least about 8 carbon atoms in the alkyl moieties and n is selected from an integer consisting of 0 and 2.

2. A paper produce comprising cellulose fibers containing about 0.3 percent to about 5 percent by weight of a sizing agent wherein the efiective sizing agent is a compound of the formula where R is selected from the group consisting of alkyl groups and alkylphenyl groups having at least about 8 carbon atoms in the alkyl moieties, and n is selected from an integer consisting of 0 and 2.

3. A sized paper product as described in claim 2 wherein the sizing agent is an alkyl 2-chloroethyl sulfide having at least about 8 carbon atoms in the alkyl group.

4. A sized paper product as described in claim 2 wherein the sizing agent is an alkyl 2-chloroethyl sulfone having at least about 8 carbon atoms in the alkyl group.

5. A sized paper product as described in claim 3 wherein the sizing agent is octadecyl 2-chloroethyl sulfide.

6. A sized paper product as described in claim 4 wherein the sizing agent is octadecyl Z-chloroethyl sulfone.

7. A method of preparing a sized fibrous product of cellulose fibers which comprises applying to the cellulose fibrous product from about 0.1 to about 5 percent by weight on the dried cellulose fibers of a sizing agent which is a compound of the formula wherein R is selected from the group consisting of alkyl. groups and alkylphenyl groups having at least about 8 carbon atoms in the alkyl moieties and n is selected from an integer consisting of 0 and 2, and drying the thus treated cellulosic fibrous product.

8. A method as described in claim 7 wherein the cellulose fibrous product is a paper product and in the sizing agent R is an alkyl group having at least about 8 carbon atoms and n is 0.

9. A method of preparing a sized paper product as described in claim 8 wherein the sizing agent is octadecyl Z-chloroethyl sulfide.

10. A method as described in claim 7 wherein the cellulose fibrous product is a paper product and in the sizing agent R is an alkyl group having at least about 8 carbon atoms and n is 2.

11. A method of preparing a sized paper product as described in claim 10 wherein the sizing agent is octadecyl Z-chloroethyl sulfone.

12. A method as described in claim 7 wherein the sizing agent is mixed with an alkali metal hydroxide prior to its being applied to the fibrous material.

References Cited UNITED STATES PATENTS 2,363,330 11/1944 Jackson et al. l62-158 X 2,802,035 8/1957 Fincke 260607 3,094,455 6/1963 Allen et al. 260607 8. LEON BASHORE, Primary Examiner. 

7. A METHOD OF PREPARING A SIZED FIBROUS PRODUCT OF CELLULOSE FIBERS WHICH COMPRISES APPLYING TO THE CELLULOSE FIBROUS PRODUCT FROM ABOUT 0.1 TO ABOUT 5 PERCENT BY WEIGHT ON THE DRIED CELLULOSE FIBERS OF A SIZING AGENT WHICH IS A COMPOUND OF THE FORMULA 